The best sealant for a leaking shower joint is a sanitary-grade, mould-resistant wet-area silicone. Choose a flexible product labelled for showers or bathrooms and confirmed by the manufacturer as compatible with every adjoining surface. Silicone can reseal a failed joint, but it cannot repair leaking plumbing, a waste connection or failed waterproofing behind the tiles.
What to look for
Choose shower silicone with:
- Wet-area suitability: Check that it is designed for frequent water exposure, rather than relying on a general “waterproof” claim.
- Mould resistance: This helps inhibit mould on the cured sealant but cannot overcome contaminated surfaces or poor ventilation.
- Surface compatibility: Confirm suitability for tile, glass, metal, acrylic or other materials touching the joint. Natural stone may require a non-staining product.
- Flexibility: The sealant must tolerate normal movement where different surfaces meet.
- Suitable curing conditions: Follow the manufacturer’s requirements for temperature, ventilation and curing time. Surface dryness does not mean the silicone has fully cured.
Colour affects appearance, not sealing performance. Durability depends mainly on product suitability, surface preparation, joint movement, cleaning products, moisture and shower use, so there is no universal lifespan.
Where silicone works
Silicone is suitable for sound joints such as internal tiled corners, wall-to-shower-base junctions and compatible shower-screen joints where the existing sealant has failed.
The old sealant generally needs to be removed, and the surfaces must be sound, clean and completely dry. Do not apply new silicone over loose, deteriorated or mould-contaminated material. Keep the shower unused for the full curing period stated by the manufacturer and ventilate the room during application.
Silicone will not fix cracked or loose tiles, concealed pipe leaks, faulty waste connections or failed waterproofing. Damp walls or floors outside the enclosure, water beneath the shower, or leakage that returns after resealing requires professional assessment.
Do not disturb concealed plumbing or waterproofing, as repairs may require appropriately licensed trades. If the source is unclear or water is escaping beyond the shower, contact our Sydney plumbing team for an assessment before resealing.